GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

1

Inspect fuse EF7.

Is fuse EF7 open?

--

Go to Step 2

Go to Step 3

2

  1. Inspect for a short circuit and repair it, if necessary.
  2. Replace fuse EF7.

Is the repair complete?

--

System OK

--

3

Measure the voltage at fuse EF7.

Is the voltage equal to the specified value?

11-14 V

Go to Step 5

Go to Step 4

4

Repair the power supply circuit for fuse EF7.

Is the repair complete?

--

System OK

--

5

Measure the voltage at terminal 5, OG, of the door lock relay connector.

Is the voltage equal to the specified value?

11-14 V

Go to Step 7

Go to Step 6

6

Repair the open circuit between fuse EF6 and terminal 5, OG, of the door lock relay connector.

Is the repair complete?

--

System OK

--

7

Use an ohmmeter to measure continuity between terminal 8, BK, of the door lock relay connector and ground.

Does the ohmmeter indicate the specified value?

0 ohms

Go to Step 9

Go to Step 8

8

Repair the open circuit between terminal 8, BK, of the door lock relay connector and ground.

Is the repair complete?

--

System OK

--

9

  1. Disconnect the door lock relay connector.
  2. Connect a fused jumper wire to the positive battery terminal.
  3. Connect another jumper wire to ground.
  4. Apply the positive jumper wire to terminal 2, WH, of the door lock relay connector.
  5. Apply the grounded jumper wire to terminal 3, D-BU, of the door lock relay connector.
  6. Switch the jumper wires so that the positive jumper is connected to terminal 3, D-BU, and the grounded jumper is connected to terminal 2, WH.

Do the doors lock and unlock when power and ground are applied to terminals 2 and 3 of the door lock relay connector?

--

Go to Step 11

Go to Step 10

10

Repair the open circuit between the door lock relay connector and S301.

Is the repair complete?

--

System OK

--

11

  1. Raise the power window in the driver's door.
  2. Disconnect the door lock connector at the top of the door lock. There are 3 connectors on the door lock. Use the schematic to verify the correct connector.
  3. Use an ohmmeter to measure continuity between terminal 2, BK, of the door lock switch connector and ground.

Does the ohmmeter indicate the specified value?

0 ohms

Go to Step 13

Go to Step 12

12

Repair the open circuit between the door lock switch connector terminal 2, WH, and ground.

Is the repair complete?

--

System OK

--

13

  1. Ensure that the door lock relay connector is connected.
  2. Touch a grounded jumper wire to terminal 1, DK GN, of the disconnected door lock switch connector.
  3. Remove the grounded jumper wire and touch it to terminal 3, D-BU, of the disconnected door lock switch connector.

Do the doors lock and unlock when terminals 3 and 1 are alternately grounded?

--

Go to Step 14

Go to Step 15

14

  1. Ensure all the lock rods are connected to the driver's door lock.
  2. If no disconnected lock rods are located, replace the driver's door lock with the integral door lock switch. Do not confuse the door lock with the lock cylinder. The door lock has 3 connectors: the lock switch, the lock solenoid, and the door contact switch. Use the schematic to verify the correct connector.

Is the repair complete?

--

System OK

--

15

Use an ohmmeter to measure the continuity between terminal 1 (D-GN) of the disconnected door lock switch connector and terminal 6, (D-GN) of the door lock relay connector.

Does the ohmmeter indicate the specified value?

0 ohms

Go to Step 17

Go to Step 16

16

Repair the open D-GN wire.

Is the repair complete?

--

System OK

--

17

Use an ohmmeter to measure the continuity between terminal 3 (D-BU) of the disconnected door lock switch connector and terminal 4 (L-GN) of the door lock relay connector.

Does the ohmmeter indicate the specified value?

0 ohms

Go to Step 19

Go to Step 18

18

Repair the open LT GN wire.

Is the repair complete?

--

System OK

--

19

Replace the door lock relay.

Is the replacement complete?

--

System OK

--